The present disclosure relates to a multilayer film material, and more particularly to chlorine-free multi-layer films and bags and pouches for ostomy use made therefrom.
Gas and odor barrier films are known and widely used in the medical and food packaging industries. Many such films have a barrier layer that contains chlorine; other barrier layers are chlorine-free. Chlorine-containing barrier layers use, for example, copolymers of vinylidene chloride vinyl chloride (VDC-VC) copolymers) and vinylidene chloride methyl acrylate copolymer (VDC-MA copolymers). These chlorine-containing films have exceptionally high malodor-causing compound barrier properties and are typically not adversely affected by the presence of moisture. One drawback to the use of chlorine-containing compounds is that these compounds, generally, present environmental issues in disposal, for example, incineration of materials after use. Another drawback is that specialized equipment is required to process these materials due to the corrosive nature of the chlorine compounds.
Barrier layers of chlorine-free material include vinyl alcohol based polymers, for example, ethylene vinyl alcohol (EVOH) copolymers and poly(vinyl alcohol) (PVOH). Unfortunately, these materials have been found to have reduced barrier performance in the presence of humidity.
Ostomy products and other applications relating to the storage of bodily liquids are highly demanding and typically subject materials used in such products to high levels of moisture. At the same time, it is extremely important that the odor barrier properties of the material are and remain high throughout their useful life. In addition, it is imperative that the mechanical strength of the material is also high and remains high for a sufficiently long period of time for extended use of the product
Other factors and properties that must also be considered in ostomy product use are the comfort of the material, as such products are worn next to the user's body, the flexibility of the material so that it conforms to the user's movements, and the quietness of the product so that wearing such a product is as audibly imperceptible as possible. The chlorine-containing materials possess these beneficial properties and qualities, but have the aforementioned environmental issues in disposal and processing.
In an effort to provide a film having the beneficial properties and characteristics of VDC-VC, VDC-MA and other chlorine-containing materials, without the detrimental effects of these chlorine-containing materials, various layered films have been composed of non-chlorine containing materials. One known film, disclosed in DE-A-4100350, is a seven layer chlorine-free film for packaging material for infusion solutions. The material is composed of a base material that is a coextruded film made of an ethylene-vinyl alcohol (EVOH) copolymer and two coating polyethylene (PE) layers onto which a PE layer and an EVOH copolymer layer are extrusion laminated.
One film used in food packaging, disclosed in EP-A-0588667, is a multiple layer film, moisture barrier material that includes a core layer made of an oxygen barrier material, such as an EVOH copolymer, two intermediate layers provided on the core layer of a propylene (PP) polymer or copolymer or a polymeric adhesive, such as a carboxylic acid or maleic anhydride-modified polyolefin such as polypropylene-based carboxylic acid or maleic anhydride-modified polyolefin. Moisture barrier layers are provided as a blend of a PP polymer or copolymer and a hydrocarbon resin, and outermost layers covering the outer surfaces are also PP polymer or copolymer.
One film used in the manufacture of ostomy pouches, disclosed in International application publication WO93/11938, is a five-layer barrier structure having a gas barrier layer, two moisture barrier layers and optionally one or more adhesive layers disposed therebetween. The moisture barrier layer is a mesophase PP-based material which contacts one or both of the sides of the gas barrier layer. The gas barrier layer is made of an EVOH copolymer.
Other multi-layer films, such as those disclosed in U.S. Pat. Nos. 4,239,826 and 4,254,169, which include an oxygen barrier layer formed of vinyl alcohol polymer or copolymers (e.g. PVOH, EVOH), and moisture barrier layers formed of partially hydrolyzed vinyl acetate polymer or copolymer, or modified polyolefins, are also known. Such films have been found to be useful in the manufacture of food packaging containers.
A five layer chlorine-free ostomy pouch film is also known. Such a film, which is disclosed in Giori, U.S. Pat. No. 7,270,860 and is incorporated herein in its entirety by reference, has a core odor barrier layer formed of a blend or a compound including amorphous polyamide, and anhydride-modified olefin polymer or copolymer. The film also includes two tie layers on both sides of the core layer and two EVA or EVA-based surface layers.
Still another film, disclosed in EP 0700777 B1, is a chlorine-free composition having a gas-barrier layer of a non-chlorine containing organic polymer which is substantially impermeable to oxygen, two tie layers each contacting one side of the barrier layer, an inner surface layer, an outer surface layer and two intermediate layers positioned between the surface layers and tie layers. The intermediate layers are an ethylene-propylene copolymer having a flexural modulus (measured according to ASTM D-882) of less than 200 MPa., preferably less than 150 MPa.
Although these films are chlorine free and thus, achieve the desired goal with respect to environmental safety, they do not fully achieve the desired combination of physical properties, including moisture and odor barrier characteristics, tear strength, comfort and “quietness”.
Accordingly, there is a need for a chlorine-free, multi-layer film for use in ostomy products that provides a barrier for malodor causing compounds. Desirably, such a film and products made therefrom maintain high barrier performance characteristics even in high moisture applications, for prolonged periods of time. More desirably still, such a film and products made therefrom exhibit high tear strength, and the products exhibit “quietness” when in use.